On the level the Chemical Factory {after Planet Notak} the last obstical is three floating barrels. If you stand on the first barrel, the third one will rise, if you stand on the last one, the first one will rise, and if you stand on the middle one, the barrels stay straight. Stand on the first one so the last barrel will rise, then take your Thermonator out and freeze the water, jump up the barrels and put your Thruster Pack on, the hold R1 and press X, you will fly op and on to the edge, then there will be 3 or more robots that Clank has to talk to.